Pocket tools, such as pocket knives, are widely used. For convenience and to prevent injury to the user, pocket knives are commonly provided with a handle and a blade which can be safely received within the handle to form a compact assembly when not in use. Prior art pocket knives generally comprise two kinds, namely those provided with a retractable blade, and those of the foldable blade type. An example of a retractable blade pocket knife is illustrated in U.S. Pat. No. 4,265,017 issued May 5, 1981 to Collins. The handle of that retractable blade knife is formed of two substantially identical halves joined together to form a cavity in which the retractable blade is received when the knife is not in use. The handle halves are held together by suitable fasteners such as deformable pins, which cooperate with a generally U-shaped bolster. To use the knife, the user must manipulate the blade to move it into the fully extended position. As can readily be appreciated from the foregoing, a pocket knife of this type has several short comings. In particular, it requires the user to manipulate the tip and sharpened regions of the blade to extend the blade before use. In addition to comprising numerous parts, such a knife also requires the use of unsightly pins and a bolster to maintain the two halves of the handles in cooperative engagement. To overcome some of these short comings, pocket knives with retractable blades have been provided with a sliding mechanism that can be activated by the user thereby avoiding direct contact with the blade. However, such a mechanism, which also typically comprises various components, necessarily protrudes from the surface of the knife handle thereby interfering with proper and comfortable gripping of the knife.
Problems associates with retractable-blade pocket knives have already been recognized and variously addressed by those skilled in the art, using among other things the benefits provided by certain pocket knives with foldable, as opposed to retractable, blades. As one of the most recent examples of a foldable blade pocket knife, U.S. Pat. No. 5,400,509 issued Mar. 28, 1995 to Collins discloses a folding knife having a unitary plastic handle configured to accommodate a blade carrier frame designed to receive the folded blade. To expose the blade, the user, nesting the handle in one hand, engages the finger notch formed near the upper edge of the blade, typically with the thumb nail of the other hand. Although the unitary handle permits the elimination of pins or other fasteners that might otherwise be flush with, and visible on, the faces of the handle, this concept requires the use of an additional component, thereby increasing the number of steps of the assembly process. Furthermore, under certain circumstances such as when the hands of the user are wet, the plastic handle may tend to escape from its nested position in the user's hand, as the user pulls on the upper edge of the blade to open the knife. As one way to overcome this undesirable slippage, handles of folding knives are often coated with a non-slip material such as rubber. Commercially available folding knives provided with non-slip coating are for example those marketed by the assignee of the present invention under the Stallion brand name, as shown at page 15 of the assignee's 1995 catalog. However, over time under certain conditions of use, the rubber coating may start peeling off the handle, thereby reducing its effectiveness and detracting from the overall appearance of the knife.
Another concept used to facilitate the opening of the blade of a folding knife is disclosed in U.S. Pat. No. 4,347,665 issued Sep. 7, 1982 to Glesser. As disclosed in Glesser, the hole formed in the enlarged upper region of the blade is engageable by the user's thumb, thereby allowing the user to open the blade with a single hand, and without making eye contact with the knife. However, to prevent the knife from slipping out of the user's hand, the user will typically have to apply lateral pressure on the knife handle with the tips of the other fingers of the hand holding the knife. In the case of the knife disclosed in the Glesser patent, the user will most likely rest those fingertips on the edge of the pocket clip for more positive retention of the knife within the hand.
The limitations identified in the foregoing make apparent that prior art pocket tools such as pocket knives or the like, have various disadvantages. Some of these prior art items include a blade actuating mechanism comprising several components assembled within the handle using various fasteners, such fasteners and mechanism being apparent on the faces of the knife handle thereby detracting from the overall appearance of these knives and impairing their ergonomic characteristics. On the other hand, the various prior art attempts to limit slippage of a pocket knife handle out of the user's hand during unfolding of the blade, for the reasons explained in the foregoing, have not been fully satisfactory. Thus, it appears desirable to provide foldable pocket knives or the like with improved features to attempt to alleviate the problems associated with conventional prior items, but which are nonetheless engineered to facilitate their fabrication, at the same time improving, or at least maintaining, their reliability and relatively low cost.